In the field of medicine, imaging and image guidance are a significant component of clinical care. From diagnosis and monitoring of disease, to planning of the surgical approach, to guidance during procedures and follow-up after the procedure is complete, imaging and image guidance provides effective and multifaceted treatment approaches, for a variety of procedures, including surgery and radiation therapy. Targeted stem cell delivery, adaptive chemotherapy regimes, and radiation therapy are only a few examples of procedures utilizing imaging guidance in the medical field.
Advanced imaging modalities such as Magnetic Resonance Imaging (“MRI”) have led to improved rates and accuracy of detection, diagnosis and staging in several fields of medicine including neurology, where imaging of diseases such as brain cancer, stroke, Intra-Cerebral Hemorrhage (“ICH”), and neurodegenerative diseases, such as Parkinson's and Alzheimer's, are performed. As an imaging modality, MRI enables three-dimensional visualization of tissue with high contrast in soft tissue without the use of ionizing radiation. This modality is often used in conjunction with other modalities such as Ultrasound (“US”), Positron Emission Tomography (“PET”) and Computed X-ray Tomography (“CT”), by examining the same tissue using the different physical principals available with each modality. CT is often used to visualize boney structures, and blood vessels when used in conjunction with an intra-venous agent such as an iodinated contrast agent. Vascular visualization may also be acquired by MRI using a contrast agent, such as an intra-venous gadolinium based contrast agent which has pharmaco-kinetic properties that enable visualization of tumors (in some instances), and break-down of the blood brain barrier. These multi-modality solutions can provide varying degrees of contrast between different tissue types, tissue function, and disease states. Imaging modalities can be used in isolation, or in combination to better differentiate and diagnose disease.
In some instances contrast agents may be used to emphasize certain anatomical regions during imaging. For example, a Gadolinium chelate injected into a blood vessel will produce enhancement of the vascular system, or the presence and distribution of leaky blood vessels. Iron-loaded stem cells injected into the body and defected by MRI will allow stem cell migration and implantation in-vivo to be tracked. For a contrast agent to be effective the contrast agent must preferentially enhance one tissue type or organ over another. Furthermore, the preferential augmentation of signal must be specific to the particular tissue type or cell of interest.
All contrast agents will shorten the MRI T1 and T2 relaxation times of nearby tissue; however, it is useful to subdivide them into two main groups. T1 contrast agents, or “positive” agents, decrease T1 approximately the same amount as T2, these agents typically give rise to increases in signal intensity in images. Examples of T1 agents are paramagnetic gadolinium- and manganese-based agents. The second group can be classified as T2 contrast agents, or “negative” agents, these agents decrease T2 much more than T1 and hence typically result in a reduction of signal intensity in images. Examples of T2 contrast agents are ferromagnetic and superparamagnetic iron oxide based particles, commonly referred to as superparamagnetic iron oxide (SPIO) and ultra-small superparamagnetic iron oxide (USPIO) particles. Furthermore, quantitative evaluation of contrast uptake can be used to evaluate blood-brain barrier disruptions and/or angiogenesis of tumors; hence, timing of contrast injection can be important in these instances.
Contrast agents can further be classified as targeted or non-targeted. A targeted contrast agent has the ability to bind to specific molecules of interest. In some cases, the T1 relaxation time of the agent significantly decreases upon binding. For example, MS-325 is an agent that binds to serum albumin in the blood. For many agents (including MS-325), the T1 relaxation time of the agent in the bound state is a strong function of the magnetic field strength. When this is the case (i.e. a molecule's T1 relaxation time is a strong function of the magnetic field strength), the molecule is said to have T1 dispersion.
Scan queue management is a particular issue when acquiring digital images with medical imaging devices, particularly in light of contrast agent introduction. For example, in an imaging study, scan queues typically consists of several series protocols. Each series protocol often consists of instructions for scanning and instructions for reconstructing the scanned images. Typically, one series protocol produces one series of images. However, with the advent of more sophisticated imaging techniques, several types of reconstruction algorithms may be applied in order to extract different information from the same data to address different clinical or research concerns. In other words, there could be multiple series of images that are derived from the same original imaging data. Traditional graphical user interfaces can be confusing as reconciliation of the scan instructions with the scanned images occurs either by knowledge of a nature of a scan and/or by understanding a naming convention of the image series.
In addition to having multiple derived image series associated with one series protocol, some imaging technique may also have a time-resolved feature where the same set of scanning instructions is repeated multiple times. In the context of MR imaging, for example, some scanners group all repeated scans in the same series while others consider each repeat as a separate series.
A time-resolved feature often requires intervention between the repeating scans. An interface first provides an alert that intervention is required, such as administering image contrast enhancing agent. The timing from such interventions to subsequent repeated scans can be crucial but can often be mismanaged due to complicated interfaces and confusing trigger instructions.
Another common confusion often occurs as a result of inconspicuous display of scan queue status. It may not be easy to discern if a series scan has started, paused but later restarted if a series protocol is currently undergoing scanning process or editing process.
Furthermore, image post-processing is often performed without feedback. Image post-processing is often time-consuming. The progress of image post-processing is often inferred by counting the number of images in an image series or after double-checking an image selection list. The long wait for feedback can be frustrating, as subsequent tasks that are to be performed after feedback (such as reviewing study completeness and/or sending images to an archival server) are delayed.